Aknowledgements

This work was supported by Grant For Visualization No.62306-01-D-B001 by the Naval Oceanographic Office and Army High Performance Computing Research Center (AHPCRC) under the auspices of the Department of the Army, Army Research Laboratory cooperative agreement number DAAH04-95-2-0003/contract number DAAH04-95-C-0008, the content of which does not necessarily reflect the position or the policy of the government, and no official endorsement should be inferred.